The slums of Manila, the capital of the Philippines, are among the most densely populated places on the planet: By some estimates, in some neighborhoods, more than 200,000 people live in a single square mile. Manhattan is almost three times less dense.

In a new photo series, German photographer Bernhard Lang documented some of the slums from above. “I have been interested in photographing slums in general to find images which show overpopulation, one of the most important and urgent global questions,” he says.

The same day he arrived, February 7, a fire broke out in part of one shantytown, the Parola Compound near the city’s port. The homes are packed so closely together that fire trucks couldn’t reach the area; some neighbors ran through the streets trying to put out the flames with buckets of water. By the next morning, more than 15,000 people were homeless.

Lang flew over the neighborhood the next morning, photographing the rubble. Fires, unfortunately, are a common occurrence. Another in January destroyed around 1,200 homes in a nearby suburb. In 2015, another fire in the Parola Compound destroyed 7,000 homes.